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Rb20det running rich after injector swap

Hi guys pretty new to this forum need help with my 1990 HCR32 Skyline. So i bought this car it had RB20DE with auto tranny i swap the gearbox to manual than replaced the motor to RB20DET using the DE harness plus the injectors. It worked fine with stock boost of 5 psi. Than i installed a bigger turbo (to4e) the car car started to ping on boost above 7 psi i changed the ecu from a rb20det very little difference was made so i went on to change the injectors to 550cc (mostplus brand) now the car runs so rich and worse than before where it used to run with rb20de injectors. Can someone guide me on the next steps so that i can get to go up till 10 or 11 psi of boost and dolve the over fueling issue . Also the why is the idle so rough. The spark plugs are so covered with carbon deposits i guess thats due to running rich. Any suggestions??

so i'll just clarify

" The spark plugs are so covered with carbon deposits i guess thats due to running rich. Any suggestions?? "

you've put bigger injectors in, haven't done anything to adjust the tune, and now it's running rich?

as Trex said...probably wheel bearing, or Johnson rod.

Your car will never run properly as the ecu you are using is not tunable. You need either an aftermarket ecu or at least a Nistune chip. If you are feeling lucky you may find Nistune or someone else will put a tune on the chip that roughly matches your set-up although i think you will need at least a Z32 afm. I assume you have fitted an intercooler of some sort? Does someone like Max Sols in Suva have a dyno?

  • Like 1

O.K
I will explain this

We are going to use some random injector values to make it easy

If your stock injectors are 250cc and at 3000rpm they are injecting at 50% of their maximum - 125cc injected
If you then put 500cc injectors in and dont change the tune to tell the ECU that there are bigger injectors in, guess what happens - 3000rpm you get 50% of the maximum - 250cc injected

It needs a tune

It needs alot of things by the sound of it

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